Protein kinase D enzymes are dispensable for proliferation, survival and antigen receptor‐regulated NFκB activity in vertebrate B‐cells

Abstract
To investigate the importance of protein kinase D (PKD) enzymes we generated a PKD‐null DT40 B‐lymphocyte cell line. Previously we have shown that PKDs have an essential role in regulating class II histone deacetylases in DT40 B‐cells [Matthews, S.A., Liu, P., Spitaler, M., Olson, E.N., McKinsey, T.A., Cantrell, D.A. and Scharenberg, A.M. (2006) Essential role for protein kinase D family kinases in the regulation of class II histone deacetylases in B lymphocytes. Mol. Cell Biol. 26, 1569–1577]. We now show that PKDs are also required to regulate HSP27 phosphorylation in DT40 B‐cells. However, in contrast to previous observations in other cell types, PKD enzymes do not regulate basic cellular processes such as proliferation or survival responses, nor NFκB transcriptional activity downstream of the B cell antigen receptor. Thus, PKDs have a selective role in DT40 B‐cell biology.